The invention is based on a fuel injection pump as defined herein. A fuel injection pump operating on the distributor principle that can also be used for direct injection in internal combustion engines having externally supplied ignition (Otto method) is already known. The fuel, furnished at feed pressure by a work piston, is distributed to the individual injection valves by a distributor shaft that rotates at half the crankshaft speed. This known pump is arranged such that at virtually the same time as the main injection that immediately precedes the ignition, a pre-injection into the working cylinder that operates offset by 360.degree. of crankshaft angle is performed. The quantity for the pre-injection is less than that for the main injection.
A disadvantage of the known pump is that both the total fuel quantity injected and the ratio of the pre-injection and main injection quantities are invariable. Nor can the onset and end of supply be varied during operation in the known apparatus. Especially from the standpoint of a sophisticated control of fuel quantity, the known fuel injection pump is unusable, because the pre-injection and main injection mutually influence one another, causing insurmountable problems in fuel quantity distribution. Hydraulic pressure waves also make accurate fuel metering impossible.